In the discussion of the background that follows, reference is made to certain structures and/or methods. However, the following references should not be construed as an admission that these structures and/or methods constitute prior art. Applicant expressly reserves the right to demonstrate that such structures and/or methods do not qualify as prior art.
A conventional cutting tool, such as a point attack bit for mining and construction, consists of one cutting end and one retention end. In operation, the retention end is positioned in a holder and the cutting end is applied against material to be mined, excavated, moved or so forth. Operation over time wears the cutting end. Once the cutting end is worn, a user removes the cutting tool and replaces it with a new or more serviceable cutting tool.
The removed worn cutting tool is typically discarded. However, even though the cutting tool is worn at the cutting end, a majority of the remaining portions of the cutting tool are still intact, a large portion of the material of the cutting tool, e.g., the steel body, remains and non-cutting end portions of the cutting tool are still functional.
Also, for every removed cutting tool, a replacement cutting tool must be delivered to the machine. The replacement cutting tools are heavy and cumbersome and transporting cutting tools can be difficult and costly, particular when delivery is to underground locations, such as in mining operations.
Reversible cutting tools are generally known: see, e.g., U.S. Pat. Nos. 3,342,531; 3,493,268; 3,519,309; and 5,810,102 and GB 1,117,112. Typically, such cutting tools are secured in a bit holder by a retaining mechanism. These retaining mechanisms typically use a retaining device, variously and for example, a retention pin, a retention clip, a plunger or a keeper, associated with the bit holder that cooperates with a recess on a cutting tool inserted into a bore of the bit holder and that biases the cutting tool to be retained in the bit holder.
By its reversible construction, reversible cutting tools has a recess associated with each end of the tool. Thus, while one recess is inserted into the bit holder for retention, a second recess is exposed. This exposed recess is used for retention when that end is inserted into the bit holder. However, prior to its use for retention in the bit holder, the recess is exposed to wear during operation when that end of the cutting tool in used for mining or construction. Such wear can detrimentally impact the retention of the cutting tool when the cutting tool is reversed.